ML20081B802

Interim Deficiency Rept,Item 55 Re Defective Spot Welds & Power-Strut Support Matl.Initially Reported on 820211. Evaluation for Spot Weld Members for Overload Conditions Continuing.Addl Use of Members Discontinued

ML20081B802
Person / Time
Site:	Fermi
Issue date:	02/23/1984
From:	Wells D DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
55, QA-84-0084, QA-84-84, NUDOCS 8403120009
Download: ML20081B802 (2)

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D n16 Donald A. Wetts vananot,anty Assnow (3i 9 23ti*E 7

{ l g y ! N ok' N o# N ae*22s Of M 2n-soo February 23,.1984 QA-84-0084 Mr. James G. Keppler, Regional Administrator Region III U. S. Nuclear Regulatory Commiasion 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Interim Report of 10CFR50.55(e) Item on Defective Spot Welds and Power-Strut Material (#55)

Dear Mr. Keppler:

This interim report involving defective spot welds and Power-Strut support material has been prepared to provide the current status of this problem.

This item was originally reported to Mr. J. E. Konklin of NRC Region III by Detroit Edison's Mr. H. A. Walker, Supervisor - Construction Quality Assurance on February 11, 1982.

It was reported at that time, that L. K. Comstock (a Detroit Edison Contractor) had noted a number of problems with spot welds on Power-Strut type PS-202 support material. This material had been ordered by the site electrical contractor, L. A. Comstock, from the Van Huffel Tube Corporation. The problem was first noted in the field when the material separated at several of the manufacturer's spot welds. As a result of this, twelve samples, (including two pieces each of Power-Strut formed metal spot welded channels representative of those used in fabrication of electrical raceway supports at Fermi 2), vere sent to Detroit Testing Laboratory. All twelve samples were destructively tested to determine spot weld quality. Tests included a peel test, macro etch, and a check for impurities.

Based on the foregoing test-results,.De'troit Ediso"n formulated an

- acceptable load criteria for evaluat' ion of spot welded Power-Strut Members. Using this criteria, Detroit Edison completed an analysis of electrical raceway' supports to determine: spot welded Power-Strut member acceptability. Conduit support containing spot welded Power-Strut members.which are built to Detroit Edison Electrical Engineering Standard Specification ~ 307.1-128 were determined to be. seismically qualified with no, additional modification. The reduced capacities of spot welded Power-Strut hembers were not the limit'ing conditions from worst case loading daaly.ws for the'various conduit support types. '

Further, with the exception of approxima'tely one hundred thirty-eight (138) supports-identified in the Reactor and Auxiliary buildings, the 8403120009 040223 gDRADOCK05000

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Mr. Jcmss G. Ksppler, Regional Administrator February 23, 1984 QA-84-0084 Page 2 balance of cable tray supports in the seismic category 1 classifica-tion were determined to be seismically qualified with no additional modification required to addreas the reduced capacities of the spot-welded Power-Strut members. Engineering identified approximately one '

- hundred thirty-eight (138) cable tray hangers in the Reactor and Auxiliary buildings which required rework to address the overload condition-of spot welded Power-Strut members, and issued appropriate rework details. Rework of tuenty-five (25) of the one hundred thirty-eight (138) cable tray hangers has been accomplished to date.

' Detroit Edison through the Architect - Engineer for cable trays add supports, Sargent & Lundy, is continuing evaluation for Power-Strut spot welded members for overload canditions induced by design changes which increase the shear stress in the welded joints, or by the cable tray hanger longitudinal bracing. This continuing evaluation is being accomplished as part of the cable tray verification program. S&L has included the Detroit' Edison criteria and analysis of this problem in the criteria and evaluations under that program.

Additional use of Power-Strut spot welded members at the Fermi 2 site, beyond those previously installed, has been discontinued. Subsequent 3

to the issue of the deviation disposition request identifying this

- matter,.the Detroit Edison. Electrical Engineering Standard Specifica-tien was revised to prohibir use of Power-Strut spot welded configurations.

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Another report on this item, either interim or ~ final, will be sent when.further information is available. If you have questions con-cerning this matter, please contact Mr. G. M. Trahey, Assistant Director - Project Quality Assurance.

Very truly yours, f

cc: Mr. Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Mr. Paul Byron, Senior Resident Inspector U. S. Nuclear Regulatory Commiscion 6450 North Dixie Highway Newport, Michigan 48166-

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